Drilling apparatus



Feb. 12, 1957 Filed June 2, 1954 D. ROBBINS DRILLING APPARATUS 5SheetsSheet 1 II" II II II II II II II II II II INVENTOR DfiY/S ROBBINSv Zda j ATTORNEYS Feb. 12, 1957 D. ROBBINS 2,781,185

DRILLING APPARATUS Filed June 2, 1954 5 Sheets-Sheet 2 i i? f -1- Bf iwk 2212,

ATTORNEZE Feb. 12, 1957 D. ROBBINS 3 DRILLING APPARATUS Filed June 2,1954 3 Sheets-Sheet 3 IN VENTOR 0/? W5 foam/V6 ATTORNEYS United StatesPatent 6 DRILLING APPARATUS Davis Robbins, Oneonta, Ala.

Application June 2, 1954, Serial No. 433,991

8 Claims. (Cl. 255-51) This invention relates to drilling apparatus andmore particularly to means for drilling holes downwardly into the earth.

One object of my invention is to provide drilling apparatus which shallembody a transmission unit mounted for vertical movement in guidewaysand means to raise or lower the transmission unit in the guidewaystogether with means connecting the unit in driving relation with a drillrod whereby the transmission unit moves downward as drilling proceeds.

Another object of my invention is to provide apparatus of the characterdesignated including improved means for connecting and disconnectingdrill rod sections to a movable transmission unit, together with amagazine mounted for pivotal movement at one side of the apparatus forholding a plurality of drill rod sections and disposed to move a sectionof the drill rod beneath the transmission unit.

further object of my invention is to provide apparatus for drillingholes downwardly into the earth which shall embody a hollow drill rodtogether with means for forcing air under pressure downwardly throughthe drill rod to clear the hole being bored of cuttings and to cool thedrill bit.

A further object of my invention is to provide portable drillingapparatus having improved means associated therewith for leveling thesame whereby the drill rod moves vertically into the earth.

A further object of my invention is to provide drilling apparatus of thecharacter designated which shall have means associated therewith fordischarging the cuttings from the hole being bored whereby the cuttingswill not interfere with the operation of the apparatus.

A still further object of my invention is to provide apparatus fordrilling holes downwardly into the earth which shall be durable, simpleof construction, economical of manufacture and which may be readilymoved from place to place and set up for the drilling operation in aminimum of time.

Apparatus embodying features of my invention is shown in theaccompanying drawings forming a part of this application, in which:

Fig. l is a front elevational view, partly broken away and in section;

Fig. 2 is a side elevational view, partly broken away and in section;

Fig. 3 is an enlarged detail sectional view taken generally along theline III-III of Fig. 1;

Fig. 4 is a plan View partly broken away and in section, showing themeans for discharging the cuttings from the hole being bored;

Fig. 5 is a sectional view taken generally along the line VV of Fig. 4;

Fig. 6 is a side elevational view, partly broken away and in section,showing the drill rod section which carries the cutting tool;

Fig. 7 is a plan view showing the means for moving the lower guides intoand out of engagement with the drill rod, the drill rod being shown insection; and

Fig. 8 is a fragmental view showing the jack member for the front of thesupporting vehicle.

Referring now to the drawings for a better understanding of my inventionI show a supporting frame embodying lower and upper horizontal plates 10and 11, respectively, connected by laterally spaced vertical framemembers 12 and 13. The vertical frame members are provided withguideways 14 and 16 which extend the length thereof, as shown in Fig. 1.The horizontal plate 10 is secured rigidly to the rear end of atransporting vehicle, such as a caterpillar tractor 17 and is supportedduring the drilling operation by hydraulic jack members 13 and 19. Eachof the jacks 18 and 19 comprises a fluid pressure operated cylinder 21having a piston rod 22 projecting from the lower end thereof. Connectedto the lower ends of the piston rods 22 are ground engaging shoe members23.

Projecting forwardly of the front end of the tractor 17 are a pair oflaterally spaced brackets 24, only one of which is shown. Pivotallyconnected between the brackets 24, by means of pins 26, is a fluidpressure operated cylinder 27 of a jack member 25. Projecting downwardlyfrom the cylinder 27 is a piston rod 28 having a ground engaging shoemember 29 connected to the lower end thereof. To limit tilting movementof the cylinder 27 about its pivot point, a U-shaped bracket 31 issecured rigidly to the upper surface of the brackets 24. The legs of theU-shaped bracket indicated at 32 and 33 are thus positioned on oppositesides of the cylinder 27 while the base 34 thereof is positioned'abovethe cylinder 27. Secured to and connecting the base 34 of the U-shapedbracket and the upper end of the cylinder 27 is a'tension spring 36which holds the cylinder in a substantially vertical position while theshoe member 29 is raised, such as when the apparatus is being moved fromplace to place. The forward portion of the. tractor 17 adjacent the jack25 is connected to the upper plate 11 by means of a brace member 37thereby adding strength to the supporting frame.

Mounted for vertical movement between the guideways 14 and 16 is atransmission unit 38 including a housing 39. Secured to the ends of thehousing 39 are roller support members 41 which carry rollers 42 thatengage opposite sides of the guideways 14 and 16, as shown in Fig. 2.Secured to the housing 39 adjacent one end thereof is one flight of asprocket chain 43 which passes over upper and lower sprocket wheels 44and 46 respectively. The sprocket wheel 44 is keyed to a transverseshaft 47 which is mounted for rotation in suitable bearings 48 and 49 onthe upper plate 11. The sprocket wheel 46 is mounted for rotation in aU-shaped bracket 51 by means of a short shaft member 52. The bracket 51is secured to the lower horizontal plate 11, as shown in Fig. 1.Connected to the housing 39 adjacent the end thereof opposite thesprocket chain 43 is one flight of a sprocket chain 53 which passes overan upper sprocket wheel 54 keyed to the shaft 47. The lower end of thesprocket chain 53 passes over a sprocket wheel 56 mounted for rotationin a U-shaped bracket 57 by means of a short shaft 58. The U-shapedbracket 57 is also secured to the horizontal plate 10.

Mounted on the shaft 47 adjacent the ends thereof are plates which aresecured to the upper ends of piston rods 64 and 66 of fluid pressureoperated cylinders 67 and 68. i The pivotal connections between the rackmembers 62 and 63 and the piston rods 64 and 66 permitlimited movementof the upper ends fthe rock members relative to I Patented lF'eb.12,1957

the pinions 59 and 61 whereby the rack members maythe lower ends thereoffor supporting :double flange.

rollers 65a which are positioned to engage opposite edges of theoutermost portions of the frame members 12 and 13, as shown in Fig. 1,whereby the rack members and piston rods 64 and 66 are held againstmovement outwardly of the frame members. To urge the rack members 62 and63 into engagement with the pinions 59 and 61 as the racks are raisedand lowered by the cylinders 67 and 68, rollers 69 and 71 are mountedfor rotation in brackets 72 and 73 respectively, on the plate 11 at theside of the racks opposite the pinions. As the racks 62 nd 63 are raisedor lowered by the cylinders the pinions 59 and are rotated therebycausing raising or lowering of the sprocket chains 43 and 53 through theshaft 4-? the sprocket wheels 44 and 54. The transmission unit 38 isthus raised or lowered by causing the sprocket chains 43 and 53 to movein the required direction.

Connected to the power unit of the tractor 17 is a horizontal shaftmember 74 having a bevel gear 76 mounted at the outer end thereof.Meshing with the bevel gear 76 is a bevel gear 77 which is secured tothe lower end of a vertical shaft 78 having a polygonal upper portion 79which extends through suitable openings in the housing 39 of thetransmission unit, as shown in Fig. 3. A suitable shear pin 80 isprovided in the shaft 73 which shears when the drill strikes a creviceor other obstruction.

Mounted within the housing 39 of the transmission unit '38 and adaptedto slide vertically along the polygonal portion 79 of the shaft 78 is asprocket wheel 31 having annular flanges $2 and 83 which slidably engagethe inner surface of the housing 39, as shown. The upper end of theshaft 78 rotates in a suitable bearing 84 mounted in the upper plate 11.

Passing through the housing 39 of the transmission unit 38 and mountedfor rotation relative thereto is a hollow driving head 36. Secured tothe driving head 86 within the housing 39 is a sprocket wheel 87. Asprocket chain 88 connects the sprockets 81 and 87 and transmits powerfrom the shaft 78 to the driving head 86.

Mounted at the lower end of the driving head 86 is a female coupling 89which is adapted to receive a male coupling 91 at the upper end of ahollow drill rod section indicated at 92. The lower end of the drill rodsection is provided with a female coupling 93 for receiving the malecoupling of a lower section 92 of the drill rod.

-As shown in Fig. 6, the first drill rod section which enters theground, indicated at 92a, is provided with a drill collar 94 havingspiral flukes 94a thereon which causes the cuttings from the hole beingbored to move in a spiral path about the outer surface of the drill rodand limits lateral shifting of the drill bit, thereby preventingexcessive wear at the sides of the bit. The drill rod section 92a isprovided with a female coupling at its lower end 1 for receiving athreaded male coupling of a drill bit 95.

Connected to the upper end of the hollow driving head 86 by means of anair swivel joint 109 is a hose 96 which communicates with a suitablecompressor, not'shown, for

. pins 114 and 116, respectively.

.are secured to the bars 104 and 106, respectively. Pivotally connectedto the upper ends of the pins 109 and 111 are lever arms 112 and 113which are fulcrumed to the upper surface of the housing members 101 and182 by Secured .to the inner ends of the bars 104 and 106 are arcu-ateguide members 117 and 118 which partially surround the drill rodsections, as shown in Fig. 7. Rollers 119 are mounted for rotation onthe inner surface of the arcuate members 117 and 118 in positiontoengage the drill rod sections as the same is rotated by the drivinghead 86. The 'arcuate guide members 117 and 118 are moved into and outof engagement With the drill rod section by the lever arms 112 and. 113and openings 121 are provided in the bars 104 and 106 for receivingsuitable pins whereby the rollers 19 of the arcuate members are held inengagement with the drill rod section during the initial drillingoperation. Also, openings 122 are provided in the bars 104 and 106 forreceiving suitable pins which engage the outer ends of thehousingmembers 191 and 1112 to limit inward movement of bars 104 and 106,whereby the arcuate members 117 and 113 are held out of engagement withthe drill rod sections, while sections are being added or removed andafter the hole has been bored a distance to prevent lateral shifting ofthe drill rod section.

Additional drill rod sections 92 are carried in a maga to the undersurface of the horizontal plate 11, as shown 'in Fig. l.

The lower end of theshaft 129 is secured to the horizontal plate 18. Thearm members 127 and 128 supplying air under pressure to the hollowdriving head.

. bars 104 and 106, which are substantially square as viewed incrosssection. Elongated openings 107 and 108 are provided in the upper Wallof the housing members-101 and 102 for receiving pins 109 and 111 whichare also connected by suitable brace members 132.

'The magazine 123 is provided with an annularrow of cup-shaped members133 adjacent the lower end thereof for receiving the lower ends of thedrill rod sections 92. The upper ends of the drill rod sections 92 areheld in the magazine by means of U-shaped members 134 having latcnmembers 136 mounted for pivotal movement adjacent the outer end of oneof the legs of each U-shaped member 134. A suitable notch 137 isprovided in the other leg of each U-shaped member for receiving the freeend of the latch member 136, as shown in Fig. 1. Due to the fact thatthe magazine rotates in bearings 124 and 126 at the outer ends of armmembers 127. and 123 which in turn are mounted for rotating movementabout the vertical shaft 129, each drill rod section may be positioneddirectly beneath the driving head 86 by merely rotating the arm membersabout the shaft 129 and then rotating the magazine in the bearings 124and 126.

Surrounding the drill rod section 92 beneath the horizontal plate 10 isa discharge housing member 133'having a bottom wall 139, side Walls 141and a top or cover 142 formed of a resilient material. The side walls141 are provided with an outwardly extending flange 143 for supportingthe outer edge of the flexible cover 1 :2. A metallic strip 144surrounds the cover 142 and is secured to the flange 143 by any suitablemeans such as rivets or bolts 146, thereby securing the flexible coverto the flange 14-3. Openings 147 and 148are provided in the bottom andcover, respectively, of the housing for receiving the drill rod sections92 or 92a, as the case may 153 is' a packing member in the form of aresilient ring 154 having downwardly tapered side walls which engage theupwardly flaring flange 153, as shown in Figs. 1 and 5. The ring member154 is split at one side thereof as at 165 whereby it may be slippedaround a drill rod section. The ring member 154 is provided with anopening 156 therein which is provided with an enlarged diameter portion157 adjacent the lower end thereof. Fitting within the enlarged diameterportion 157 and secured to the ring member 154 is an annular sealingmember 158 having a downwardly and inwardly extending flange 159 whichengages the outer surface of the drill rod 92 to form an air tight sealtherewith. The housing 138 is provided with an outlet conduit 161 fordischarging the cuttings from the hole being bored.

Fitting over the ring member 154 is a clamp ring 162 which is in theform of a pair of semi-circular members 163 and 164 pivotally connectedat one side thereof by means of a bolt 166. Projecting outwardly fromthe members 163 and 164 are handle members 167 and 168, respectively.The clamp ring 162 is locked in place by means of bracket members 169and 171 mounted at opposite sides of the annular member 152, as shown inFigs. 1 and 4. The brackets 169 and 171 are provided with oppositelydisposed horizontal slots therein for receiving the handle members 167and 168 when the clamp ring 162 is rotated in a counterclockwisedirection, as viewed in plan.

To support the drill rod sections 92 while the uppermost one is beingremoved, I secure transverse pipe sections 172 to the walls of the drillrod section 92 adjacent the upper ends thereof. The pipe sections 172connect opposite sides of the drill rod sections, there being suitableopenings in the drill rod sections for receiving the pipe sections 172as shown in Figs. 1 and 6. The pipe section 172 is joined to the wallsof the drill rod section 92 by any suitable means, such as by welding,whereby there is no escape of air as the air passes downwardly throughthe drill rod section. Mounted on the undersurface of the horizontalplate by any suitable means, such as by welding, is a rearwardlyextending bracket 174 having a cylindrical sleeve member 176 secured tothe outer end thereof. The sleeve member 176 is in position to receive asuitable bar member which passes through the adjacent pipe section 172to support the drill rod sections remaining in the hole being boredwhile the uppermost section is being removed. By providing thetransverse pipe sections 172, there is a relatively long bearing areafor the bar member which passes therethrough, thus preventing excessivewear to the walls of the drill rod sections.

A transverse pipe section 173 similar in all respects to the pipesection 172 is provided adjacent the lower end of the drill rod sectionsfor receiving a suitable bar, whereby the uppermost drill rod sectionmay be held against rotation while the female section 89 of the drivinghead 86 is unscrewed from or screwed onto the male coupling 91.Preferably, the pipe sections 172 and 173 are positioned atsubstantially right angles to each other, as shown. Thefemale sectionsare screwed onto and unscrewed from the male sections by rotating thedriving head 86 in reverse directions.

The vertical frame members 14 and 16 are provided with joints 177 and178 whereby the upper portions thereof may be moved downwardly onto thetractor 17 when the apparatus is being transported a great distance onanother vehicle, such as a truck or the like. A suitable hinge 179connects the upper and lower portions of the vertical frame members 14and 16, as shown in Fig. 2. In view of the fact that the jacks 67 and 68are carried by the upper portion of the frame members 14 and 16 and arenot connected to the lower portions thereof, they move with the upperportions as the upper portions move toward lowered and raised positions.The vertical shaft 129 carrying the magazine 123 is disconnected fromthe remainder of the apparatus when the upper portions of the framemembers are lowered onto the tractor. 17. 7

vertical frame members are held in upright position while the apparatusis in operation by means of the brace member 37 and by horizontalbracket members 181 and 182 welded to the upper and lower portions ofthe vertical members, respectively. The bracket members 181 and 182 areattached to each other by means of bolts 183, as shown in Fig. 1. Toraise and lower the upper portions of the frame members 12 and 13, afluid pressure operated cylinder 184 is pivotally mounted on the plate10. Projecting outwardly of the upper end of the cylinder 184 is apiston rod 186 which is pivotally connected to the frame members.

From the foregoing description, the operation of my improved drillingapparatus will be readily understood.

The apparatus is transported to the area where the holes are to bebored, such as a strip mining area, and the vertical frame members 14and 16am moved to the upright position by means of the cylinder 184. Thebrace member 37 is mounted between the upper plate 11 and the tractor1'7 and the bolts 183 are installed thereby locking the upper portionsof the vertical frame members to the lower portions thereof. Theapparatus is then moved by the tractor 17 to the position where a holeis to be drilled into the earth. The shoe members 23 and 29 are loweredinto engagement with the ground and the apparatus is then leveled byraising or lowering the jacks 18, 19 and 25 as required.

With the apparatus thus leveled, the arms 127 and 128 carrying themagazine 123 are swung around and the magazine is rotated so as toposition the drill rod section 92:: beneath the driving head 86. Thedriving head 86 is then rotated in a direction to screw the femalecoupling 89 onto the male coupling at the upper end of the drill rodsection 920. The arcuate guidemembers 117 and 118 are moved intoengagement with the outer wall 1 of the drive rod section, as shown inFig. 7. A shallow hole is then drilled into the ground by rotating thedriving head 86 through the medium of the sprocket chain 88, the shaft78 and the driving shaft 74 which is connected to the tractor 17. Afterthe shallow hole is drilled into the earth, the guide members are movedout of engagement with the drill rod section 92a and the section israised by actuating the pressure operated cylinders 67 and 68 in adirection to raise the racks 62 and 63, thereby raising the flights ofthe sprocket chains 43 and 53 which are attached to the transmissionunit 38. With the drill rod section 92a thus raised, the ring member 152in the discharge housing 133 is positioned beneath the recess 97 in thelower plate 10 and the drill rod section 92:: is passed downwardlythrough the ring member 152 and the opening 147. The resilient splitring member 154 is then placed around the drill rod section, as shown inFig. 5 with the inwardly extending flange 159 in sliding contact withthe outer surface of the drill rod. The clamp ring 162 is then placedaround the drill rod section and rotated in a counterclockwise directionwhereby it engages the brackets 169 and 171 and locks the resilientpacking member 154 within the annular member 152. By providing aresilient cover 142 for the discharge housing 138, the drill rod sectionremains in a vertical position while the housing accommodates itself tothe contour of the earth surrounding the hole being bored.

With the discharge housing 138 thus mounted beneath the plate 18, thecylinders 67 and 63 are actuated to cause rotation of the sprocketchains 43 and 53 in a direction to lower the transmission unit 38together with the drill rod section 92a. The driving head 86 and thedrill rod section are then rotated by the sprocket chain 88, the shaft78 and the drive shaft 74. When the upper pipe section 172 in the drillrod section 92a moves to a position opposite the sleeve member 176, asuitable bar is placed through the sleeve member and the pipe section,thereby holding the drill rod section against rotation and supportingthe same. With the drill rod section locked in place by the rod, thedriving head 86 is rotated in a reverse direction to unscrew the femalecoupling 89 from the male coupling of the drill rod section 92a. Thetransmission unit 38 is raised and the magazine is swung around toposition a drill rod section 92 beneath the driving head 86. The drivinghead 86 is then rotated in a direction to screw the female coupling 89thereof down onto the male coupling 91 of the drill rod section 92. Thefemale coupling at the lower end of the drill rod section 92 is thenscrewed onto the male coupling at the upper end of the drill rod section92:; by rotating the driving head 86. The cylinders 67 and 68 are nextactuated so as to raise the transmission unit 38 a slight distancewhereby the rod member may be removed from the pipe section 172 and thesleeve member 176. Continued rotary motion is imparted to the drill rodsection 92 until the pipe section 172 moves to a point opposite thesleeve member 176, whereupon another drill rod section is added asdescribed above.

As the drill rod sections are rotated the drill bit 95 cuts into theearth. Compressed air is introduced through the hose connection 96 andflows downwardly through the driving head 86 and the hollow drill rodsections 92 and 92a thence out through the male coupling of the drillbit 95 where it picks up'the cuttings from the hole being bored andconveys them upwardly about the outer surface of the drill rod sectionto the discharge housing 138 where the cuttings are discharged throughthe conduit 161. The downwardly and inwardly extending flange 159 on thesealing member 155 prevents air and the cuttings from being blown outaround the drill rod sections.

To remove the drill rod sections from the drilled hole, the transmissionunit 38 together with the drill rod sec- 'tions are raised by actuatingthe cylinders 67 and 68. The bar is inserted through the sleevemember176 and the pipe section 172 of the second drill rod section 92 wherebyit is held against rotation and supported. The female joint at the lowerend of the uppermost drill rod section 92 is then unscrewed from themale coupling at the upper end of the second drill rod section byreversing the direction of rotation of the driving head 36. The magazine123 is then swung around into position to receive the drill rod sectionwhich is attached to the driving head 86. A suitable bar is then placedthrough the pipe section 173 at the lower end of the drill rod section92 thereby holding the same against rotation while the driving head 86is rotated in a direction to unscrew the female coupling 89 from themale coupling 91. The magazine is then swung outwardly to the positionshown in Fig. 1. With the uppermost drill rod section 92 removed, thetransmission unit 33 is lowered by the cylinders 67 and 68 to place thefemale coupling 89 of the driving head into engagement with the malecoupling of the next drill rod section. The driving read 86. is thendriven in a direction to screw the female coupling 89 thereof onto themale coupling of the next drill rod section. The transmission unit 38together with the driving head 36 and the drill rod sections are thenraised by actuating the cylinders 67 and 68 and the second drill rodsection is removed in the same manner as the first. This procedure iscontinued until all of the drill rod sections are removed from theopening and placed in 'the magazine.

After all of the drill rod sections have been removed from the hole, theannular sealing member 154 of the discharge housing 138 is removed byrotating the clamp ring 162 in a clockwise direction. The drill bit 95is then passed upwardly through the annular member 152. The dischargehousing 133 is then removed from beneath the plate 1% and is transferredto anew location Where a hole is to be bored. The shoes of the hydraulicjacks 18, 19 and 25 are next lifted by actuating the cylinders 21 and27. The apparatus is then transferred by From the foregoing it will beseen that I have devised an improved apparatus for drilling holesdownwardly into the earth. By providing portable drilling apparatus.together with improved means for connecting and disconnecting drill rodsections, my apparatus is particularly adapted for drilling holes forexplosives in strip mining areas. Also, by providing hollow drillsections together with means for forcing compressed air downwa'rdlythrough the same and the drill bit, the cuttings are removed immediatelyfrom the hole and the drill head is cooled continuously. Furthermore, byproviding a vertically movable transmission unit together with 1 -eansto drive the same from a polygonal shaft during the vertical movement,my apparatus is simple of construction, economical of manufacture andrequires a minimum of personnel to operate the same.

In actual practice I have found that my improved apparatus issatisfactory in every respect and that the same may be moved from placeto place and set up for operation in a very short period of time. Also,I have found that the actual drilling time required, after the apparatusis set up, is reduced materially over apparatus heretofore known to me.

While I have shown my inventionin but one form, it will beobvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof, and I desire, therefore, that only such limitations shall beplaced thereupon as are specifically set forth in the appended claims.

What I claim is: V a

1. Drilling apparatus for drilling holes ,downwardl into the earthcomprising a vertical frame, vertical guideways in the frame, apolygonal rotary driving shaft mounted to rotate in the frame andcarried thereby, means for rotating said driving shaft, a transmissionunit mounted for vertical movement in the guideways, means connectingthe transmission unit in driving relation with the polygonal shaft,'ahollow drill rod adapted to convey air from an air pressure sourcedownwardly to clear the hole being bored of cuttings, a hollow drill bitconnected to' the lower end of the drill rod, meansdetachably connectingthe drill rod to and driving the same from the transmission unit, adischarge housing for said cuttings surrounding the drill rod adjacentthe lower end of the vertical frame, and power means connected to thetransmission unit to raise the transmission unit in the guideways and tolower the transmission unit as drilling proceeds.

2. Drilling apparatus as set forth in claim 1 inwhich the drill rod issectional and in which a magazine for holding sections of the drill rodis pivotally mounted alongside the frame in position for a section ofthe drill rod and a portion of the magazine to be swung between theguideways beneath the transmission unit to be connected thereto.

3. Drilling apparatus as set forth in claim 1 in which the guide meansfor the drill comprises a pair of horizontally extending arcuate membershaving rollers mounted for rotation along the inner surfaces thereof andpositioned to receive the drill rod therebetween and means for movingsaid arcuate members whereby the rollers move into and out of engagementwith said drill rod.

4. Drilling apparatus for drilling holes downwardly into the earthcomprising a vertical frame, vertical guideways in thefrarne, atransmission unit mounted for vertical movement in said guideways, powermeans for raising and lowering said transmission unit, a vertical rotarydriv-.

to said transmission unit for driving the same, a hollow driving headdriven by the transmission unit, a hollow drill rod adapted to conveyair from an air pressure source downwardly to clear the hole being boredof cuttings, a hollow drill bit connected to the lower end of the drillrod, means connecting an air pressure source to said hollow driving headand means for connecting the driving head to the upper end of the drillrod,

5. Drilling apparatus as defined in claim 4 in which the power means forraising and lowering the transmission unit comprises verticallyextending endless sprocket chains mounted for rotation in the samedirection adjacent each side of the transmission unit, means connectingone flight of each of said chains to said transmission unit, a driveshaft mounted for rotation adjacent the upper end of the vertical frame,sprocket wheels on said shaft for driving the sprocket chains in thesame direction, at least one pinion mounted on said shaft, a rackmounted on the vertical frame in position to engage and rotate saidpinion, and fluid pressure operated means for moving said rack relativeto said pinion.

6. Drilling apparatus for drilling holes downwardly into the earthcomprising a vertical frame, vertical guideways in the frame, atransmission unit mounted for vertical movement in said guideways, powermeans for raising and lowering said transmission unit, a rotary drivingshaft connected to said transmission unit for driving the same, meansfor rotating said driving shaft a sectional drill rod comprising aplurality of individual hollow sections, a hollow drill bit connected tothe lower end of the drill rod, means to connect the individual sectionsand to drive the drill rod from the transmission unit, means introducingair from an air pressure source downwardly through the hollow drill rodand the drill bit, seal-means positioned outwardly of and adjacent theupper end of the hole being bored and surrounding the drill rod fordischarging air moving upwardly through the hole together with thecuttings entrained with the upwardly moving air, and support means onsaid frame adapted to engage the drill rod and support the lowersections of the drill rod while the uppermost section is being removed.

7. Drilling apparatus as defined in claim 6 in which the means forsupporting the lower sections of the drill rod while the uppermostsection is being removed comprises a pipe section extending transverselythrough the upper portion of each drill rod section, a bracket securedto the lower portion of the frame, a sleeve member secured to saidbracket and positioned opposite said pipe section, and a rod-like memberdisposed to pass through said sleeve member and said pipe section.

8. Apparatus as set forth in claim 7 in which transversely extendingpipe sections are also provided in the lower portion of the individualdrill rod-like member sections for receiving a rod whereby the uppermostsection may be held against rotation while it is being disconnected fromthe transmission unit.

References Cited in the file of this patent UNITED STATES PATENTS1,065,409 Van Sickle June 24, 1913 1,242,305 Arey Oct. 9, 1917 2,114,305Johansen Apr. 19, 1938 2,145,939 Markley Feb. 7, 1939 2,202,446 EsselingMay 28, 1940 2,215,928 Hornbrook Sept. 24, 1940 2,527,255 Hunt Oct. 24,1950 2,557,049 Haines June 12, 1951 2,594,098 Vanderzee Apr. 22, 19522,660,403 Roland Nov. 24, 1953

